The present invention relates to an integrated singulation system and method for singulation and inspection of semiconductor devices. The present invention has particular applicability in the automated process of singulation and inspection of semiconductor devices in which only the semiconductor devices which passed an electrical test are inspected.
Semiconductor devices, such as integrated circuit (IC) chips are manufactured in strips. During the manufacturing process, each semiconductor device in the strip of semiconductor devices is electrically tested, cut into individual semiconductor devices in a singulation process and inspected. The electrical test determines if the semiconductor device is operating according to electrical specifications for the semiconductor device. The inspection also determines whether the semiconductor is within the proper physical dimensions for the semiconductor device. If a semiconductor device fails either test, then the semiconductor device is discarded. Conventional testing of semiconductor devices is a time-consuming process.
In conventional testing systems, a strip of semiconductor devices would be electrically tested, each semiconductor device being tested individually. However, xe2x80x9cstrip testingxe2x80x9d is becoming more popular. In strip testing, a group of semiconductor devices are tested at the same time. Currently, 16 or 32 semiconductor devices can be tested at the same time. Therefore, strip testing has greatly reduced the testing time required to test the semiconductor devices.
Although strip testing has reduced the testing time, each semiconductor device is inspected regardless of whether the semiconductor device failed the electrical test. Since the inspection of each semiconductor device for physical dimension conformance is still performed one at a time, the inspection of a semiconductor device that is destined to be discarded for failing the electrical test is unnecessary. Therefore, it would be advantageous to discard semiconductor devices which fail the electrical test and do not need to be inspected.
There exists a need for an integrated singulation and inspection process for semiconductor devices, thereby reducing the inspection time and increasing production throughput.
These and other needs are met by embodiments of the present invention which provide a method and system for only inspecting semiconductor devices which have passed an electrical test and discarding the semiconductor devices which failed the electrical test.
The integrated singulation machine of the present invention includes a memory storing test results indicating whether a plurality of singulated semiconductor devices passed an electrical test, a processor for reading the test results stored in memory and a sorter, controlled by the processor, for sorting the semiconductor devices and discarding singulated semiconductor devices which failed the electrical test. The integrated singulation machine saves time by discarding semiconductor devices which failed the electrical test rather than unnecessarily inspecting the singulated semiconductor devices to ensure that they are within the proper physical dimensions.
The integrated singulation system of the present invention an optical code reader for reading a code marked on a semiconductor device which is part of a strip of semiconductors, wherein the code indicates the test result of whether the individual semiconductor device passed an electrical test and a singulation machine. The singulation machine cuts the strip of semiconductor devices into individual semiconductor devices and further comprises a memory for storing the result of the electrical test for each semiconductor device, a processor for reading the test results stored in memory and a sorter, controlled by the processor, for sorting the semiconductor devices and discarding the semiconductor devices which failed the electrical test. The optical code reader assists in determining whether to automatically discard the semiconductor devices by reading the test results which indicate whether the semiconductor devices passed the electrical test.
The method of the present invention is for inspecting semiconductor devices. The method comprises the steps of reading a code on a semiconductor device in a strip of semiconductor devices, wherein the code indicates whether the semiconductor device passed an electrical test, singulating the strip of semiconductor devices into individual semiconductor devices and automatically discarding the semiconductor devices in which the code indicates that the semiconductor device failed the electrical test, in response to reading of the code on the semiconductor device. Automatically discarding the semiconductor devices that failed the electrical test, ensures that time is not wasted inspecting the physical dimensions of the semiconductor devices.
Additional advantages of the present invention will become readily apparent to those skilled in this art from the following detailed description, wherein only the preferred embodiment of the present invention is shown and described, simply by way of illustration of the best mode contemplated for carrying out the present invention. As will be realized, the present invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.